1. Field of the Invention
The present invention relates to methods for adjusting the frequencies of electronic components such as piezoelectric oscillators and surface acoustic wave devices, and more specifically, the present invention relates to methods for adjusting the frequencies of electronic components via ion-beam etching.
2. Description of the Related Art
Conventionally, in piezoelectric oscillators and surface acoustic wave devices, a conventional method for adjusting the frequency thereof includes irradiating an electrode disposed on a piezoelectric substrate with an ion beam to perform etching thereon. In this case, the piezoelectric substrate having the electrode disposed thereon is arranged in a fixed manner. The ion beam is applied from an ion gun arranged in a fixed manner at a predetermined distance from the surface on which the electrode of the piezoelectric substrate is disposed.
In addition, in Japanese Unexamined Patent Application Publication No. 8-181558, there is provided a method for changing the distance between an ion gun and an electronic component in order to control an etching speed. Furthermore, in Japanese Unexamined Patent Application Publication No. 4-196707, Japanese Unexamined Patent Application Publication No. 4-196708, and other publications, there are provided apparatuses for changing the directions of ion beams with magnetic fields and electric fields to allow only neutral particles to collide with the electrodes of electronic components.
An ion beam has an intensity distribution. Thus, as in the conventional methods, when ion beams are simply applied from the ion gun arranged in the fixed manner with respect to the electrode of an electronic component, variations in the processing amount occur according to positions. As a result, depending on the type of electronic components, the processing variations significantly influence the characteristics thereof, with the result that the frequency of the electronic components cannot be adjusted with high quality and high accuracy.
The processing variations caused by the ion-beam etching can be reduced to some extent by varying the distance between the ion gun and the electronic component, discharging conditions, and the configuration of a beam emitting hole. However, with such solutions, there is a limitation to reduction of the process variations.
In addition, when a very small part such as the electrode of an electronic component is irradiated with an ion beam to be etched, if a slight deviation of the center of the ion beam occurs, the symmetry of a region for etching is destroyed, with the result that the influence on the characteristics is even more increased. Therefore, the adjustment of the position of the ion gun requires very high accuracy. Thus, there is a problem in that the maintenance and adjustment of the ion gun is very complicated.
In order to overcome the problems described above, preferred embodiments of the present invention provide a method for adjusting the frequency of an electronic component which minimize variations in etching when an ion beam etching is performed on the electrode of the electronic component to achieve highly accurate frequency adjustment. In addition, with the method of preferred embodiments of the present invention, the frequency adjustment can be performed with high quality and high accuracy, while simplifying complicated work such as the maintenance and adjustment of an ion gun.
Preferred embodiments of the present invention provide a method for adjusting the frequency of an electronic component device by irradiating an electrode disposed on a surface of the electronic component device with an ion beam to perform etching, in which the ion beam irradiation is performed while moving at least one of the electronic component device and the ion beam in directions along the surface on which the electrode is disposed.
In one preferred embodiment of the present invention, the ion beam irradiation is performed while moving at least one of the electronic component device and the ion beam in one direction along the surface on which the electrode is disposed.
In another preferred embodiment of the present invention, a surface acoustic wave device defines the electronic component device and includes an interdigital transducer having a plurality of electrode fingers disposed on a surface of a piezoelectric substrate, and the ion beam irradiation is performed while moving at least one of the surface acoustic wave device and the ion beam in a direction in which the electrode fingers extend.
In another preferred embodiment of the present invention, when the ion beam irradiation is performed, the ion beam is bent by applying an electric field or a magnetic field.
In the method for adjusting the frequency of an electronic component according to another preferred embodiment of the present invention, an electrode of the electronic component device or a substrate is etched by ion-beam etching to achieve highly accurate frequency adjustments. In this case, the ion beam irradiation is performed while moving at least one of the electronic component device and the ion beam in directions along a surface on which the electrode is disposed. Thus, variations in the etched amount of a region for etching are minimized, with the result that the frequency adjustment is performed with high quality and high accuracy.
In the conventional method, the ion beam irradiation is performed by arranging an ion gun and an electronic component device in a fixed manner. Thus, symmetry of the processing amount is destroyed when the center of the ion beam even slightly deviates, thereby causing an increase in influences on the characteristics of the electronic component. In contrast, in the present invention, since ion beam irradiation is performed while moving at least one of the electronic component device and the ion beam in the directions along the surface on which the electrode is disposed, the processing symmetry is prevented from being destroyed. Thus, the positioning and maintenance of an ion gun can be simplified and results in much more accurate frequency adjustment.
Particularly, when the ion radiation range is made broader than the surface on which the electrode of the electronic component device is disposed, it is unnecessary to adjust the positions of both ends of the range in which the ion beam is moved relatively thereto. As a result, the positioning and maintenance of the ion gun is much easier.
When the ion beam irradiation is performed while moving at least one of the electronic component device and the ion beam in directions along the surface on which the electrode is disposed, it is only necessary to move at least one of the electronic component device and the ion beam only in a certain direction. As a result, great advantages are obtained with the simplified apparatus and control.
For the purpose of illustrating the present invention, there is shown in the drawings several forms that are presently preferred, it being understood, however, that the present invention is not limited to the precise arrangements and instrumentalities shown.
Other features, elements, characteristics and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments thereof with reference to the attached drawings.